Hearing aid



FIG. 1 is a front and right side perspective view of hearing aid of the present invention;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a top view thereof;

FIG. 7 is a bottom view thereof; and,

FIG. 8 is a rear and left side perspective view thereof.

The broken line showing of hearing aid is included for the purpose of illustrating environment and forms no part of the claimed design. 

The ornamental design for a hearing aid, as shown and described. 